Well bore caliper with helically traveling feeler



Patented July 11, 1950 WELL BORE CALIPER WITH HELICALLY TRAVELING FEELER William E. Barnes, Beaumont, Ten, assignor to Sun Oil Company, Philadelphia, Pa., a corporation of New Jersey Application December 12, 1946, Serial No. 715,845

. 4 Claims. 1

This invention relates to calipering devices and more particularly to a type of measuring and recording instrument adapted to be passed through a pipe line or the like to indicate and record the internal condition of the pipe.

Pipe and tubing used in industrial operations to transport fluids of a corrosive nature and subject to pressures, either internal or external, become unsafe due to corrosion or pressure or a combination of both. Deformations causing variations from a true circular cross section impair the efliciency of the pipe and weaken the structure. If conditions of maximum safety and operating efliciency are to be maintained, it is necessary to check the condition of the pipe or tubing from time to time and replace defective sections. It is impractical to periodically remove and subject the tubing to shop tests to determine these weaknesses. Devices for indicating the internal conditions of pipes or tubing known as calipering and recording devices have been designed for passage through the tubing while it is in place and in operation. These devices usually include a plurality of small wheels or feelers urged into contact with the interior surface of the tubing and connected to a recording device in a manner to scribe the normal internal surface conditions of the tubing and variations from the normal internal surface configuration of the tubing on a chart. The calipering and recording devices of this type have been particularly useful in oil well fields since they may be readily lowered into a well tubing or passed through a pipe line to indicate and record the internal conditions of the pipe or tubing. The present invention relates generally to this type of calipering and recording device.

It is a principal object of this invention to provide an improved calipering and recording device which is arranged to rotate while passing through tubing being examined causing a feeler arm to effect a spiral contact path on the inner wall of the tubing and to transmit the internal variations of the traced path to a recording chart contained within the device, thereby indicating the condition of the pipe.

It is a further object of this invention to provide a calipering and recording device capable of indicating deviations from true circular crosssection in pipes or well tubes as well a variations of the internal surface caused by erosion and other operating conditions.

It is also an object of this invention to provide an improved calipering and recording device for determining the internal surface and diameter variations of a pipe or well tube and recording of the deviations from the normal on a chart.

Further objects and advantages of thi invention will be apparent by referring to the following specification and drawing in which,

Figure 1 is a longitudinal section of the calipering and recording device of this invention.

Figure 2 is an end elevation taken on the line 22 of Figure 1.

Figure 3 is a cross-section on the line 3-3 01' Figure 1.

Referring to the drawings, the mechanism is enclosed in a tubular supporting framework or housing Ill of a diameter somewhat less than the internal diameter of the pipe to be examined. One end of the housing is closed by the end wall II to which is preferably fastened a threaded connection l2 for the reception of a line for lowering the housing into the well tubing or for the reception of other means for advancing the housing through a pipe. The other end of the supporting framework or housing I0 is provided with an opening l3 through which is extended the feeler arm assembly.

The tubular. housing Ill encloses a body member l4. One end of the body member I4 provides a block portion generally indicated at l5 which receives a sleeve member l6 as indicated. The other end of the body member I4 is tubular to provide a chamber C for a recording stylus ll, recording strip l8 and associated mechanism for effecting the record on the recording strip I8. It should be noted that the body member I4 is rotatably mounted within the housing ill by means of bearing surfaces shown diagrammatically at l9-l9. Fastened to the center of end wall 2| of body member I! is a sleeve 22 enclosing a shaft 23; The sleeve 22 terminates in a worm 24 and is rotatable therewith about shaft 23 and in turn causes rotation of body member I4. The shafst 23 is rigidly secured in end wall I l as shown a The body member I4 is driven by a friction drive wheel 26 which projects through an opening 21 in the housing Ill and is supported on and keyed to the shaft 28, on which is also keyed the gear 29 arranged to mesh with the worm 24. In order to provide suflicient frictional contact be-' tween the drive wheel 26 and the pipe wall, an idler .wheel 30 is adapted to extend through a second opening in the housing "I diametrically opposite to the opening 21. The idler wheel 30 is supported on a pivotal arm 3| which normally positions the wheel 3. outwardly of the housing It in response to the pressure of the leaf spring 32.

Guiding and centering springs 33 are fixed at 3 radial points about the exterior of the housing It b near the feeler end of the device to properly center the device as it passes through the tubing. In passing through tubing the friction drive wheel 28 in contact with the inner wall of the tubing will be rotated causing actuation of gear 23 and worm 24 and since the worm 24 is fixed to the body member l4 through sleeve 22, the body member l4 will be rotated within the housing as the housing is moved through the tubing being examined.

As previously described, the feeler end of the body member [4 carries a sleeve it which is rotated therewith. An end of the sleeve projects through the opening l3 of the housing In and an arm 34 is secured thereto which extends radially beyond the housing, and to the arm 34 is pivotally secured a feeler lever 35 (Figure 2) having" that a rotatable feeler wheel be provided, 'al- ,though it is desirable to avoid excessive frictional contact with the tubing wall. A link 31 connects the feeler lever 35 with one end of a cross arm 38, whose other end is secured to a shaft 39' mounted for rotation within sleeve l6. Ann 38 and link 31 provide a bell crank arrangement so that as the feeler wheel 36 contacts a depression in the tubing wall, the shaft 39 is actuated. A tension coil spring 40 connecting the arm 38 and the radial arm 34 normally urges the feeler wheel 36 outwardly in engagement with the internal surfaces of the tubing being examined. When the shaft 39 is actuated in accordance with depressions or variations from normal surface conditions of the tubing, the stylus l1 connected to the shaft 39 will in turn be activated.

From the foregoing description it will be understood that, as the housing In is moved through the tubing, the body member I4, actuated by the drive wheel 26, gear 29 and worm 24, will be rotated. The radial arm 34 will rotate with the body member l4 in a plane transverse to the axis of the tubing and thus the feeler wheel 38 is caused to describe a spiral path on the tubing inner wall as the housing I is advanced through the tubing being examined. Hence, any variations of internal surface configuration from true circular cross-section will cause an inward or outward radial movement of the feeler wheel 36, which actuates the stylus shaft 39 and moves the stylus ll relative to the surface of the recording strip l8. Suitable drivingmechanism for the recording strip is provided to be operated by the friction drive wheel 26. This includes a gear wheel 4| terial, such as metal strip, photographic paper, etc., although ordinary paper may be preferred. The record strip may be provided with a center line 3|, as shown in Figure 3, which is located to conform to a Po ition of the stylus corresponding to the normal configuration and diameter of the tubing being examined. Variations of internal surface configuration or internal diameter of the tubing from the normal condition are indicated on the strip l3 by variations from the normal line 5|, which variations will be effected by movement of stylus I1.

which may be called a sun gear and is fixed to the free end of shaft 23 and arranged to mesh with planet gear 42 carried by the shaft 43 extending longitudinally of chamber C and suitably journaled in the chamber end walls. It will be seen then that when the body member I4 rotates relative to the housing l0, the planet gear 42 will be caused to walk around the fixed sun gear 4| and cause the shaft 43 to rotate. The shaft 43 is provided with a worm 45 arranged to mesh with gear 43 (Figure 3) on sprocket wheel 41 which receives record strip l 3 from a supply spool 43 and advances it to the take-up spool 43. The driving connection between sprocket 41 and takeup spool 49 may, for example, take the form of a spring belt 50.

The record strip I3 may be of any suitable ma- While the invention has been particularly described with respect to a form adapted for callpering oil well tubing, it should be understood that the device finds utility in determining conditions of the internal surfaces of varying lengths of pipes or conduits. The record strip, when the device is used in tubing containing fluid, will be of a type inpervious to harm by the fluids. And it will also be understood that various forms -of driving mechanisms may be used to obtain the spiral progression of the feeler arm through the tubing.

Having described my invention, what I claim and desire to protect by Letters Patent is:

1. A pipe calipering device comprising a supporting framework adapted to be moved through a pipe to be calipered, a body member rotatably supported within said framework, means to rotate said body member as the supporting framework is moved through" the pipe, said rotating means including a friction drive wheel geared to the body member and adapted to contact the pipe wall and be rotatably driven as the framework moves through the pipe, a feeler arm having 2. Apparatus for calipering tubular members comprising a tubular casing having an opening in its lower end, a support rotatably mounted within said casing, said support including a lower bearing portion and an upper housing portion, a sleeve extending axially of the support and below said aperture in the casing, a stylus shaft rotatable within said sleeve and bearing portion and having a stylus at its upper end, a transverse arm having one' end fixed to the lower end of said sleeve and its other end pivotally. receiving a feeler lever, and a bell crank arrangement secured between said shaft and said feeler lever.

13. Apparatus for calipering tubular members comprising a tubular casing having an opening in its lower end, a support rotatably mounted within said casing, driving means for rotating the support as the casing is moved through the tubular member, said support including a lower bearing portion having'a sleeve extending axially of the support and below said opening in the casing and an upper housing portion for receiving a recording chart, a stylus shaft rotatable within said sleeve and bearing portion and having a, stylus at its upper end, a transverse arm having one end fixed to the lower end of said sleeve and its other end pivotally receiving a feeler lever, and a bell crank arrangement secured between said shaft and said feeler lever to eflect movement of said stylus shaft as the feeler lever encounters pits or depressions in the inner wall of the tubular members.

4. Apparatus for calipering tubular members comprising a tubular casing having an opening 5 in its lower end, a support rotatably mounted within said casing, said support including a lower bearing portion and an upper housing portion, a sleeve extending axially of the support and below said aperture in the casing, a stylus shaft 10 Number rotatable within said sleeve and bearingportion and having a stylus at its upper end, a transverse arm having one end fixed to the lower-end of said sleeve and its other.end-pivotally receiving a feeler lever,'and a bell crank arrangement :seq cured between said shaft and said feeler lever to effect movement of said shaft, means for rotating said support as the casing is moved through the tubular member being calipered to provide a helical course for said feeler lever and effect movement of said stylus shaft.

WILLIAM E. BARNES.

REFERENCES CITED The following references are of record in th file of this patent:

UNITED STATES PATENTS Name Date 2,074,753 McClain Mar. 23, 1937 2,102,080 Kinley Dec. 14, 1937 2,239,811 Cuppers Apr. 29, 1941 FOREIGN PATENTS Number Country Date 512,091 Great Britain Aug. 29, 1939 OTHER REFERENCES Oil and Gas Journal, pp. 46, 47, Jan. 6, 1945. 

